Farewell, Friend(1986)

Wataru and Makoto are two singers and on their way from a performance to an interview when they are ambushed. Their attackers, who identify themselves as the "Noblemen Squad" take Makoto hostage and leave Wataru and their female manager behind. Luckily, the manager's brother (Ren Osugi, here working under the pseudonym Kyoji Saeki) drops by and starts training Wataru so he can rescue his partner.